Fishing float construction

ABSTRACT

Foamed lower olefin polymers, particularly foamed low density polyethylene are used for the construction of extremely durable floats for commercial fishing nets, lobster pots and crab pots. A multi-chambered float in which a tubular inner wall is connected at its ends to a spaced surrounding outer wall and in which the inner wall is connected to the outer wall by radially extending spacing walls is used to provide a float of high buoyancy. The outer wall is convexly configured and the float manifests a substantially greater diameter at its midsection than at the ends. The float walls provide waxy surfaces of low moisture absorptivity.

[ Apr. 25, 1972 United States Patent Price et al.

[54] FISHING FLOAT CONSTRUCTION FOREIGN PATENTS 0R APPLICATIONSCanada........................

V l a h 85 55 99 ll 3 26 74 ll 6 52 55 [72] Inventors: Kenneth E. Price,El Monte; Edwin E.

Presby, West Covina, both of Calif.

[73] Assignee: Rainbow Lifegard Products Inc., El

Monte, Calif.

Primary Examiner-Melvin D. Rein Attorney-Christie, Parker & Hale Jan.22, 1970 [22] Filed:

ABSTRACT Foamed lower olefin polymers, particularly foamed low densitypolyethylene are used for the construction of extrem durable floats forcommercial fishin crab pots. A multi-chambered float ely [2]] Appl. No.:

g nets, lobster pots and in which a tubular inner wall is connected atits ends to a spaced surrounding outer wall and in which the inner wallis connected to the outer wall 505 232 494 a a L u x3 3 2 4 .2 "4

U S CI Int. Cl.

F 1]] 2 8 555 [ill g walls is used to provide a float of wall isconvexly configured and the m r .1 w. d .l F wk m a .I e w ne a t r Ya DO .m afl 3 frde 9 mam o m UtTV m ms l n ud C .lh d O 3 n m mYmMa XCS mtriau II n t floa k .lUm db h a t m ms w Vii-O0 bhflfil ameter at itsmidsecprovide waxy surfaces of 43/43 1 ....43/43.l X 43/43 1 X [56]References Cited UNITED STATES PATENTS 2,790,187 4/1957 Marconi3,103,199 9/1963 Gagnon..... 3,038,375 6/1962 Gansz PATENTED APR 2 5 m2SHEET 10F 2 H lll Arraar/EV! FISHING FLOAT CONSTRUCTION BACKGROUND OFTHE INVENTION In recent years expanded vinyl floats have supplanted manyconventional wood and cork floats in the commercial fish and shellfishindustries. Expanded vinyl floats, however, sufier several deficiencies.

Floats used near head end of a seine net, namely the end of the netconnected to a seine drum of a commercial fishing vessel, are subjectedto severe compressive loads when the net is paid out and brought in.Expanded vinyl floats under such loads are, in many instances,compressed to 50 percent or less of their original volume. When new,these floats return to their original volume when the compressive loadis released As use continues, however, the floats fatigue and lose theirability to return to their original volume, and as a consequence, thebuoyancy originally provided is lost to a substantial degree.

The expanded vinyl floats may also be severely scored under such loads.When badly scored, the float tears and snags with the net or is tornfrom the net. As a consequence, expanded vinyl floats may not beeconomically used at the very head end of the net.

Another disadvantage, of no small consequence, is that the expandedvinyl floats are frequently partially destroyed by sea mammals. Toooften the degree of destruction is sufiicient to cause the float to loseits required service buoyancy and the float sinks. This results in alost of expensive shellfish equipment when the floats are used to markcrab and lobster pots.

SUMMARY OF THE INVENTION It has been found that floats of unusualdurability and service life can be constructed from foamed lower olefinpolymers, particularly foamed low density polyethylene.

Using foamed lower olefin polymers, floats of unusual rigidity and highbuoyancy may be obtained by a construction which comprises a tubularinner wall adapted to receive a line rope or chain, an outer wall,connected to the opposed ends of the tubular inner wall and surroundingand spaced from the tubular inner wall between the end connections and aplurality of radially extending walls which connect the tubular innerwall and surrounding outer wall. This construction provides amulti-chambered float in which both air and foamed olefin polymercooperate to provide buoyancy and in which buoyancy is maintained if oneor more of the chambers is punctured.

Foamed olefin polymer floats provided in accordance with the practice ofthis invention are rigid and retain their structural shape even underthe severest compressive loads, including the hydrostatic loadsencountered when the floats use buoy underwater nets for trapping bottomfeeding fish, and buoyancy after extended periods of severe use. Inaddition, the tough, smooth surface provided by foamed olefin polymersmakes the floats unusually resilient to scruffing, scarring, tearing andattack by sea mammals.

DRAWINGS FIG. 1 illustrates a complete fishing float constructionaxially cut to illustrate chambered construction.

FIG. 2 illustrates a sub assembly which is one half of a fishing float.

FIG. 3 illustrates one alternate float configuration available whichemploys the basic chambered float construction of this invention.

DESCRIPTION According to the present invention there is providedunusually durable, highly rigid floats of foamed lower olefin polymersfor commercial fish and shellfish applications.

The foamed lower olefin polymers which may be used in the constructionof floats according to the practice of this invention are foamedethylene polymers and foamed propylene polymers. These include ethylenehomopolymers, propylene homopolymers, copolymers of ethylene with minoramounts of ethylenically unsaturated comonomers polymerizable therewithand copolymers of propylene with minor amounts of ethylenicallyunsaturated comonomers polymerizable therewith. Among the comonomerswhich may be suitably polymerized with ethylene there may be mentionedpropylene, butene, acrylic acid, ethyl acrylate, ethyl acetate, vinylacetate and like. Suitable comonomers for polymerization with propyleneinclude, among others, ethylene, butene and the like.

The preferred olefin polymers are ethylene homopolymers. Theparticularly preferred ethylene homopolymers are the low densitypolyethylenes having a density of from about 0.910 to about 0.925 andmixtures of low density polyethylene with minor amount of medium densitypolyethylenes having a density of from about 0.926 and about 0.940and/or high density polyethylenes having a density of from about 0.941to about 0.965 or more.

The lower olefin polymers employed in the construction of the floats ofthis invention display an ability to form tough skinned, fairly rigid,non brittle, closed cell foam structure when molded or extruded. Thefoams, however, do possess a degree of elasticity which allows thefloats to withstand shocks and compressive loads without rupture.Further, they provide a waxy surface of low moisture absorptivity. Thesecharacteristics allow construction of chambered floats of unusualstructural rigidity and resistance to compressive and abrasive forces.

With reference now to FIG. 1 which is an axial cut of float for use onseine drum fish nets and the like, the multi-chamber floats of thisinvention comprise a substantially tubular inner structural wall 10which is suitably dimensioned to receive, in slidable relation, ropes,lines, chains or the like. Outer wall 12 is connected to the tubularinner wall at the opposed ends thereof and surrounds said inner wall inspaced relation. Radially extending spacing walls 16 connect saidtubular inner wall and surrounding outer wall to form a float having aplurality of chambers, each chamber being formed by the cooperation of aportion of the tubular inner wall 10, a portion of the surrounding outerwall 12 and two radially extending spacing walls 14.

Although the radially extending walls are shown projecting radially fromthe axis of the tubular inner wall and in complete contact with theinner wall and outer wall, it will be understood that other structuralarrangements are available. The walls 16 may for instance extend at anangle to the axis of tube 10 or spiral about inner tubular wall 10. Inaddition, they may be formed to a length abbreviated with respect to thelength of inner wall 10 so as to provide open communication betweenchambers. Further, they may be provided with cross walls for increasedrigidity.

With particular reference to FIG. 2 a float of an external configurationsuitable for use as a float for fishing nets such as seine nets and thelike may be prepared by molding two mating halves, each having theconfiguration shown in FIG. 2 and joining the halves by a suitablesealing means with the rings 18 of inner wall 12, rings 20, outer wall14, and ribs ends 22 of radially extending walls suitably aligned todefine a plurality of chambers.

Equally suitably, however, would be the insertion of a punched disc (notshown) between two halves to form a float having twice as many chambersas provided by each half of float.

Although the relative external dimensions employed in the constructionof the float may vary widely, depending on the intended end useapplication, it has been found that employing structural wallthicknesses generally on the average of from about three-sixteenths inchto about one-fourth inch provides a float of suitable rigidity and highbuoyancy which will withstand continuous service for extended periods oftime.

Several distinctive advantages are available from floats constructed inthe manner illustrated by FIGS. 1 and 2. Since a substantial volume ofthe float is air, the float is highly buoyant. For example, employingfoamed low density polyethylene, a 210 gram, six chambered ellipticallyshaped 5 inches fishing net float having about a 2 inches minordiameter, a 4 inches major diameter, a bore diameter of an inch, and anaverage wall thickness of 0.25 inch, can be expected to support about640 grams of lead without submerging.

Employing multi-chamber construction also allows one or more chambers tobe punctured without a material loss in buoyancy.

The radial extended spacing walls also impart a high degree of rigidityto the float in that even at high compressive loads, compression of thefloat is minimal. The tough lower olefin polymers provide a lowfriction, waxy surface which aids in the laying of a net in a fishingarea and materially resists attack from sea mammals in that, unlike thefoamed vinyl floats, they experience considerable difficulty in graspingthe waxy surface of the float.

Service life of such floats is unusually high even under severeconditions. For example, under controlled conditions, floats constructedof the configuration shown in FIGS. 1 and 2 attached to the very headend of a seine net remained unaffected by even the hardest servicerequirements at points in time and use where floats constructed ofexpanded vinyls failed. In addition, they did not compress or fail atthe very end of the net where vinyl floats cannot be employedeconomically.

Based on data collected, service lives of several heavy fishing seasonsmay be expected whereas expanded vinyl floats under similar conditionsfail in less than a fishing season.

The basic float construction of this invention is also equally adaptivefor the fabrication of lobster and crab pot floats. Lobster pot floatsare basically right cylinders having a truncated conical end at one endand a closed flat end. A suitable construction for them is shown in FIG.3. Fabrication may be from three or more pieces. Piece 24 is conical andmates with cylindrical section 26 which, in turn, is end-capped withsection 28 to provide a multi-chambered float. The combined constructionprovides the tubular inner wall 10, the connected outer wall 12 formedby the outer walls of conical section 24, cylinder 26, and end wall 28,and the radially extended spacing walls 16 provided by the spacing wallsof the conical section 24 and right cylinder 26.

A crab pot float construction may be readily achieved by substituting aconical section 24 for cap wall 28 of FIG. 3.

As will be readily appreciated, the basic sections from which a floatcan be constructed may be readily fabricated by a variety of means.

Elliptically shaped halves for a conventional float for a fishing net aswell as conical sections for crab and lobster pots may be fabricated byconventional foam molding techniques. Typically, the lower olefinpolymer already containing a suitable foaming agent such as theazo-compounds, N-nitroso compounds, sulfonyl hydrazides and the like;anti-oxidants; ultra violet absorbing agents and the like and wheredesired, a cross linking agent such as the peroxides, are heated in asuitable extrusion apparatus to a temperature above the melting point ofthe lower olefin polymers and the decompositioned or expansiontemperature of the foaming agent and maintained at a pressure too highfor the melt to expand. The molten lower olefin polymer is then injectedin a controlled quantity less than the volume of the mold into asuitable mold at a reduced pressure at which the polymer is allowed tofoam and fill the mold. Upon suitable cooling, the part can be ejectedand two halves connected by conventional heat-sealing, solvent-sealing,ultrasonic welding and like measures.

Cylindrical sections such as section 16 of FIG. 3 may be molded in anidentical manner or extruded continuously through a die where again theethylene polymer melt is maintained in the extruder at a pressure whichis too high to allow expansion. Upon extrusion to a shaping die thepolymer is allowed to uniformly expand to provide cylindrical sections16. The continuously formed sections may then be suitably cut to anydesired length for construction of either lobster pot or crab pot floatsand the like, using similar connecting measures.

For more details of such foam molding and sealing measures there isincorporated herein, by reference, 1969-1970 Modern PlasticsEncyclopedia, Vol. 46, N0. 10 a, McGrawhill, Inc.

The basic float constructions may also be suitably color coded toidentify the owner of the float and his fishing nets, crab pots orlobster pots.

While the novel floats of this invention have been described in terms ofa novel float construction providing a multiplicity of chambers, it isto be understood that it is within the sphere of this invention toconstruct floats of any configuration as long as there is used for theconstruction of the float a foamed lower olefin polymer.

What is claimed is:

l. A chambered fishing float construction comprising:

a. a substantially tubular inner wall;

b. an outer wall connected to said inner wall by opposed end walls,outer wall being configured to form a symmetric convexly curved outersurface with he diameter of the float at its midsection beingsubstantially greater than that of the ends: and

c. a plurality of spacing walls extending radially from said inner walland connecting said inner wall and said outer wall, said float beingformed from a foamed low density olefin polymer selected from the groupconsisting of low density polyethylene and polypropylene polymers, andsaid tubular inner wall, said outer wall and said spacing wallsindependently having an average wall thickness of from aboutthree-sixteenths inch to about one-fourth inch.

2. A chambered fishing float claimed in claim 1 in which the polymer islow density polyethylene.

3. A chambered fishing float as claimed in claim 1 in which the polymeris a low density polypropylene.

1. A chambered fishing float construction comprising: a. a substantiallytubular inner wall; b. an outer wall connected to said inner wall byopposed end walls, outer wall being configured to form a symmetricconvexly curved outer surface with he diameter of the float at itsmidsection being substantially greater than that of the ends: and c. aplurality of spacing walls extending radially from said inner wall andconnecting said inner wall and said outer wall, said float being formedfrom a foamed low density olefin polymer selected from the groupconsisting of low density polyethylene and polypropylene polymers, andsaid tubular inner wall, said outer wall and said spacing wallsindependently having an average wall thickness of from aboutthree-sixteenths inch to about one-fourth inch.
 2. A chambered fishingfloat claimed in claim 1 in which the polymer is low densitypolyethylene.
 3. A chambered fishing float as claimed in claim 1 inwhich the polymer is a low density polypropylene.